1. Technical Field
The present invention relates to automobile power supply control devices, more specifically, to a device for controlling power supply transition according to the operation of a switch in an automobile including a push button type operation switch.
2. Related Art
Historically reviewing the power supply transition of the automobile, only two transitions states with simply OFF (stop state of engine) and ON (operation state of engine) originally existed, but the ON state divided into two states of IGON (operation state of engine) and START (startup state of engine) according to the appearance of the electrical engine startup device (ignition motor), and now three transitions states “OFF”, “IGON” and “START” exist. In the course of history, an “ACC” for enabling power ON of only electrical components is added between “OFF” and “IGON” according to the appearance of various types of electrical components (accessories) such as a radio, and nowadays, the majority of automobiles perform steering wheel lock and the like in the “OFF” state from the standpoint of security, whereby “OFF” is referred to as “LOCK” and four transitions states of “LOCK”, “ACC”, “IGON”, and “START” are consequently provided.
Such power supply transition is entrusted on the operation of the driver, where a mechanical key type rotary switch has been widely used from the past for the operation unit, but an ignition device using an electronic key that can be simultaneously used with the mechanical key has appeared in recent years. In the electronic ignition device, authentication is wirelessly performed between an electronic key (portable device) held by the driver and an authentication unit 16 mounted on a vehicle to permit power supply transition such as engine startup. One of such ignition device includes an engine startup device equipped with a push button type operation switch (sometimes simply referred to as push switch) (see e.g., Japanese Unexamined Patent Publication No. 2001-351453).
In such engine startup device, a momentary type push switch is arranged, and the power supply transition state of the automobile is switched every time the push switch is pushed. Specifically, as described in paragraph of the relevant document, switch is sequentially made in the order of LOCK→ACC→IGON→START→LOCK every time the push switch is pushed.